Traffic Adaptive Energy-Saving Algorithm For Wireless Transceivers

In wireless local area network based IEEE 802.11 standard, wireless transceiver of node can use license-free ISM (Industrial, Scientific, and Medical Bands) radio band to communicate with others. Thus, most of mobile computing devices, such as portable computers, PDAs (Personal Digital Assistant) and so on, have equipped with IEEE 802.11 wireless network interface card to facilitate access to the wireless networks. Because these mobile devices are powered by the limited battery energy, reducing the power consumption becomes one of the current research hot spot at home and abroad.Given the energy consumption of wireless transceiver accounts for a significant proportion, IEEE 802.11 standard introduces power management, which allows nodes switch to sleep mode in the absence of data transferring. That can achieve the goal of saving energy by turning off wireless transceiver. Based on the above power management strategies, we mainly do some research on the the wireless transceiver energy efficiency in wireless infrastructure networks. We proposed a Traffic Adaptive Sleeping Schedule (TASS) strategy for it.Time is divided into fixed length time slot in TASS strategy. The length of time slot is the multiple of Beacon intervals. The scheduling sequence denotes the node's statuses, which are awake status (including receive, send and idle) and sleep status. We use Markov model to derive a lot of measurement formula, such as the average numbers of sleep time slots, the length of sleep time, the average numbers of awake time slots, the length of awake time, the average numbers of listening beacon, the average numbers of state switching, the total energy consumption of the node. In addition, we give an optimization model of optimized total energy consumption. Finally, we use MATLAB to design the program, when network traffic obeys Poisson distribution and Gamma distribution. We do the numerical test and analysis of TASS. Numerical analysis shows that the proposed TASS can reduce the energy consumption of the wireless transceiver.